Annealing hardening and deformation behavior of layered gradient Zr–Ti composite

Abstract

To investigate potential strengthening approaches, multi-layered zirconium–titanium (Zr–Ti) composites were fabricated by hot-rolling bonding and annealing. The microstructures of these composites were characterized using scanning electron microscopy with energy dispersive spectroscopy (SEM–EDS) and electron backscatter diffractometry (EBSD). Their mechanical properties were evaluated by uniaxial tension and compression measurements. It was found that the fabricated Zr–Ti composites are composed of alternating Zr/diffusion/Ti layers, and chemical compositions of Zr and Ti showed a gradient distribution in the diffusion layer. Compared with as-rolled samples, annealing can strengthen the layered gradient Zr–Ti composite, and this is mainly caused by solid-solution strengthening and microstructure refinement-induced strengthening. Compared with the raw materials, a synergistic improvement of strength and ductility is achieved in the Zr–Ti composite as a result of the layered gradient microstructure. Tension–compression asymmetry is observed in the Zr–Ti composites, which may be attributed to twinning and microvoids induced by unbalanced diffusion.